George Cohen, director of the Federal Mediation and Conciliation Service, said Monday the parties had agreed to use the agency. He assigned three mediators to assist negotiations — deputy director Scot Beckenbaugh, director of mediation services John Sweeney and Commissioner Guy Serota — who was removed later in the day because of a Twitter account that may have been tampered with.

The sides are to meet separately with the mediators Wednesday.

"While we have no particular level of expectation going into this process, we welcome a new approach in trying to reach a resolution of the ongoing labor dispute at the earliest possible date," NHL deputy commissioner Bill Daly said.

Cohen has worked with the players' associations for Major League Baseball, helping end the 1994-95 strike as an outside counsel, and the NBA. He was an adviser to the NHL players' union before joining FMCS three years ago.

"We look forward to their involvement as we continue working to reach an equitable agreement for both the players and the owners," said Donald Fehr, executive director of the NHL Players' Association.

Cohen mediated during the 2010 negotiations in Major League Soccer and 2011 talks in the NFL and NBA, along with this year's dispute between the NFL and its on-field officials.